Refrigerating apparatus



- June 1934. 1-1. M. GRAHAM REFRIGERATING APPARATU? 2 Sheets-Sheet 1Filed June 29, 1933 INVENTOR flv'olziM. (ifafiam ATTORNEYb' June 5,1934.

H. GRAHAM REFRIGERATING APPARATUS Filed June 29, 1933 2 Sheets-Sheet 2-ATTORNEYS Patented June 5, 1934 1,961,212 REFRIGERATING APPARATUS HaroldM. Graham, Buffalo, N. Y., assignor to Ross Heater & Mfg. Co. Inc,Buffalo, N. Y., a corporation of New York Application June 29, 1933,Serial No. 678,203

11 Claims. (Cl. 62-152) This invention relates to vacuum producingequipment of the kind which utilizes steam ejectors to maintain therequired degree of vacuum" in the working chamber of the apparatus withwhich the equipment is associated.

Equipment of the character generally. described includes a condenser forcondensing the steam discharged from the ejectors, a vacuum of as high adegree as practical being maintained in the condenser in order tofacilitate condensation of the steam. The degree of vacuum that can bemaintained in the working chamber is dependent, among other factors,upon the degree of vacuum that is maintained in the condenser while thedegree of vacuum thatcan be maintained in the condenser is dependentamong other factors, upon the temperature of the cooling water that iscirculated through the cooling tubes of the condenser. It will beapparent, therefore, that the degree of vacuum that is maintained in theworking chamber, assuming that other factors remain constant, will varyin accordance with the temperature of the water which is circulatedthrough the cooling tubes of the condenser.

In order, therefore, to compensate for variations in the temperature ofthe cooling water which is circulated through the condenser and in orderto compensate for variations in the load upon the equipment, asrepresented by the work to be performed in the working chamber, forexample,

the maintenance, of the temperature of a refrigerating medium at apredetermined value, it is the practice to provide means, both manuallyand tion of the refrigerating medium through the apparatus with whichthe equipment is associat-- ed in the event that, as a result ofabnormal con-- ditions, the back pressure in the condenser increases, oris likely to increase, to such a value that its capacity will beinadequate for the purpose in view.

The invention is illustrated in connection with air conditioningapparatus. It is to be understood, however, that this is by way ofexample only as the advantages of the invention may be obtained by itsuse in connection with various types of apparatus, for example,refrigerating, water cooling and similar systems.

The invention is illustrated in the accompanying drawings, in which:

Figure l is a view partially in elevation and partially in section ofair conditioning apparatus in which features of the invention areincorporated.

Figure 2 is a top plan view of that part of theapparatus in whichthecooling of the refrigerating medium is effected.

automatically controlled, for regulating the supply of steam to theejectors. If, for any reason, for example, failure of the pump whichcirculates the cooling water through the tubes of the condenser with theattendant-increase in the temperature of the cooling water, steam shouldback up into the working chamber then the refrigerating medium would,unless provision were made to guard against this, be heated instead ofcooled. This condition would be aggravated in equipment in which thesupply of steam is automatically controlled as the amount of steamdelivered to the ejectors would bev automatically increased as thedegree of vacuum in the working chamber decreased. The circulation of awarm or hot medium through cooling tubes or coils of the apparatus withwhich the equipment is associated would be highly objectionable,especially if the apparatus were designed for the conditioning of air orthe preservation of foods.

The object of the present invention is to provide means forautomatically stopping circula- Figure 3 is a view similar to Figure 1of a second embodiment of the invention.

Figure 4 is a similar view of a third embodiment of the invention.

The air condition apparatus, as illustrated, includes a tank 5 which isadapted to provide a cooling chamber 511 into which the refrigeratingmedium is introduced through a pipe 6, a body of the refrigeratingmedium preferably being maintained in the cooling chamber. The pipe 6 ispreferably perforated so that the refrigerating medium is introduced inthe form of a spray. Ejectors 7 and 7a maintain a vacuum of the requireddegree in the chamber 5a, preferably an absolute pressure of the orderof .15 pounds. The temperature of the refrigerating medium in thechamber 5a is, therefore, lowered to a temperature which corresponds tosuch pressure. The refrigerating medium is withdrawn from the chamber50. through an-outlet pipe 8 by a pump 9. The latter, which ispreferably of a centrif-- ugal type, causes the said medium to flowthrough a pipe 10 and a valve 10a in said pipe to the cooling tubes orcoils of the apparatus, the said tubes or coilsbeing sufiicientlyindicated by a showing of the casing 11 therefor. From the cooling tubesor coils of the apparatus the refrigerating medium is conducted by apipe 12 to the pipe 6 by which it is reintroduced into 'the chamber 5a..

The ejectors 7 and la include steam supply pipes 13 and 14 respectively.A valve 15 is lo;- cated in the pipe 13 while a similar valve 16 isUnder normal operating conditions one or more of the ejectors will, inthe average installation, be inoperative, such ejector or ejectors beingutilized only when the apparatus is operating under a maximum load. Inthe embodiment illustrated, the temperature responsive elements 17 areindependently operative to regulate the valves 15 and 16 to maintain therefrigerating medium at the temperature desired, For example, theelement associated with the valve 15 may be conditioned to hold the saidvalve open so long as the temperature of the refrigerating medium ismaintained at a temperature of the order of 45 F. or'higher while theelement associated with the valve 16 may be conditioned to open thelatter when the temperature of the refrigerating medium raises to'avalue of the order of F. or higher.

The ejectors 7 and 7a] arearranged in a. header 18 which is carried bythe tank 5. The steam and the entrained vapors are discharged throughthe difiuser throats 19 and 20 of the ejectors into a condenser 21, thelatter being provided with conduits 22 and 23 with which the difiuserthroats 19 and 20 respectively, communicate. The condenser 21 is dividedby a partition 24 into chambers 25 and 26, the ejector 7 dischargingthrough the conduit 22 into the former and the ejector 7a. dischargingthrough the conduit 23 into the latter. A relatively high vacuum'ismaintained in the chambers 25 and 26. To this end ejectors 27 and 28 areemployed. Theformer communicates with the chamber 25 through a pipeconnection 29 while the latter communicates with the chamber 26 througha pipe connec tion 30.

The ejectors 27 and 28 discharge into an auxiliary condenser 31, avacuum being maintained in the said condenser by an ejector 32. Theejector 32 is connected to the condenser 31 by a pipe 32a and itdischarges into a condenser 33,

which is in communication with the atmosphere through a vent 34. Inorder to cut off communication between the condensing chambers 25 and 26through the auxiliary condenser 31 when either of the ejectors 7 or 7ais inoperative, the pipe connections 29, and 30 are preferably providedwith valves 35 and 36, respectively.

The condensate from the condensing chambers 25 and 26 is withdrawn froma common hot-well 37 by a pump 38. The condensate which accumulates inthe chamber 26 is conducted to the hotwell 37 by a pipe 39, the latterbeing formed or provided with a U-shaped section or trap 40 throughwhich the condensate must flow in. its passage to the hot-well. Thecondensate in the trap 40 is adapted to prevent a back-flow between thechambers 25 and 26 through the pipe 39 when, as a result of theejector'm bein'g'inoperative, the absolute pressure in the coolingchamber 5a, and

hence the absolute pressure in the condensing chamber 26, is higher thanthe absolute pressure in the condensing'chamber 25. The legs of the trapare so formed that the differential in pressures between the chambers 25and 26 will not be high enough, when the ejector 7a is inoperative,

to force the liquid which provides the seal out oi" the trap.

The cooling tubes 41 of the condensing chambers 25 and 26 are seriallyconnected by suitable headers, one of which is shown at 42. The coolingwater'is introduced into the inlet chamber of the header 42 through apipe 43. It flows through the tubes in the chamber 25 and returnsthrough the tubes in the chamber 26 tothe outlet chamber of the header42. From the outlet chamber it is discharged through a pipe 44. The saidpipe is connected to the inlet of a pump 45, the outlet of the pumpbeing connected by a pipe 46 to the top of a cooling tower 47 ofconventional construction. The water which cools as it passes downwardlythrough the tower is discharged through an outlet pipe 48. The latter isconnected to the pipe 43 through which the cooling water is introducedinto theinlet chamber of the header 42.

The amount of steam that is supplied to the ejectors 7 and 7a isregulated so that the temperature of the refrigerating medium will bemaintained at therequired value, the amount of steam being increased asthe temperature of the refrigerating medium raises above such value. If,for any reason, therefore, such as; for example, failure of, the pump-i5with the attendant increase in temperature of the coolingwater, in thecondenser tubes 41, a portion of the steam is not condensed but backs upin the cooling chamber 5a the refrigerating medium will, unlessprovision is made to guard against this, be heated. In this connectionit is understood, of course, that as the temperature of the coolingwater in the tubes 41 rises there is a corresponding back pressure builtup in the condensing chamber, such back pressure increasing, as thetemperature of the cooling Water increases, until there is a back flowof the steam into the cooling chamber 5a. In the em bodiment illustratedthe amount of steam which is supplied to the ejectors is automaticallyincreased as the temperature of the refrigerating medium increasesbeyond the required value. The condition described would, therefore; beaggravated in installations of this kind. The circulation of a heatedmedium through the cooling tubes or coils of the apparatus with whichthe equipment is associated is highly objectionable if not involvingelements of danger, this being especially true in the case of airconditioning apparatus. In accordance with the invention means isprovided wherebyin the event that a back pressure builds up in thecondensing chambers 25 and 26, for example. as a result of the failureof the pump 45, and as a result of this the capacity of thecondenser isrendered inadequate for the purpose in view, circulation of therefrigcrating medium is automatically suspended. The said means includesthe valve 101: which is located in the pipe 10. The valve is connectedto a temperature responsive element 50 (Figure l) which is located inthe cooling chamber 5a preferably above the level of the body ofrefrigerating medium. The said element is adapted to automatically closethe valve 10a when the temperature in the cooling chamber 51: increasesto a predeterminedvalue, for example, F. Thus,

'while the pump 45 may continue topoperate there chamber 5a is loweredto a predetermined value, for example, 65 F. it will open the valve 10aand again permit circulation of the refrigerating medium through thetubes or coils of the air conditioning apparatus.

From the foregoingit will be apparent that if there is an interruptionin the circulation of the cooling medium through the tubes 41 and, as aresult of this the capacity of the condenser is so reduced that steambacks up in the cooling chamber, the circulation of the refrigeratingmedium, will be automatically suspended until the temperature of thecooling chamber is again normal.

In the embodiment illustrated in Figure 3 the valve 10a is controlled bya pressure responsive element 51 which is located in the condensingchamber 26, preferably adjacent the bottom thereof. The said element isadapted to close the valve me when the back pressure in the chamber 26increases to such a value that there is, or is a possibility of, a backflow of steam to the cooling chamber 5a. In this connection it isunderstood, of course, that such an increase in the absolute pressure inthe chamber 26 could be caused, among other factors, by a suspension inthe circulation of the cooling water through the tubes in the condensingchamber as a result of the failure of thepump 45. The element 51 isoperative, when the absolute pressure in the chamber 26 is lowered tosuch a value that substantially all the steam entering it will becondensed, to open the valve 10a and permit a resumption in thecirculation of the refrigerating medium through the tubes or coils ofthe air conditioning apparatus. It will be apparent, therefore, that inthe event'of failure of the pump 45 circulation of the refrigeratingmedium will be suspended until it is repaired.

In the embodiment illustrated in Figure 4 the valve 10a is controlled bya temperature responsive element 52 which is located in a section 53 ofthe conduit 48. The element 52 is adapted to close the valve 10a whenthe temperature of the cooling water in the conduit 53, and hence in thetubes 41, is of such a value that, owing to the corresponding value inthe absolute pressure in the chamber 26, there is a possibility of aback flow of the steam into the cooling cham ber 5a. Thus when the pump45 fails and circulation of the cooling water through the tower issuspended, with an attendant rise in temperature of the cooling water inthe tubes 41, circulation of the refrigerating medium through the airconditioning apparatus will also be suspended. As soon as' thecirculation of the cooling water through the tower is resumed and thetemperature of the water is lowered to the required value, the element52 is operative to open the valve 10aand permit a resumption in thecirculation of the refrigerating medium. In other respects the apparatusillustrated in Figures 3 and 4 is substantially the same as that shownin Figure l. r

From the foregoing it will be apparent that r so long as cooling waterof the required temperature is circulated through the tubes of thecondensing chambers, the ejectors 2'7 and 28 will maintain the requiredabsolute pressure in the said chambers and the steam will be'condensedas fast as it enters them. Each of the embodiments of the inventioncontemplates an arrangement whereby, the circulation of therefrigerating medium through the apparatus with which the equipment isassociated is automatically suspended in the event that the backpressure in supplying steam from said supply lineto said the condensingchambers increases to such an ex-,

tent that a back flow of steam is created. In other words, if, for anyreason, the capacity of the condenser becomes inadequate for-the purposein view circulation of the refrigerating medium is suspended until thecapacity of the condenser isagain normal.

I claim as my invention:

"1. The combination with refrigerating apparatus, of equipment forcooling the refrigerating medium which is circulated through saidapparatus including a chamber through which said refrigerating medium iscirculated, a steam ejector for evacuating said chamber to lower thetemperature of the refrigerating medium as it passes therethrough, meansfor condensing'the steam discharged from said ejector and means,operative upon said last named means becoming inoperative to such adegree that a back flow of steam into said chamber is likely to result,'for stopping the circulation of the refrigerating medium through saidapparatus.

2. The combination with refrigerating apparatus, of equipment forcooling the refrigerating medium which is circulated through saidapparatus including a; chamber through which said refrigerating mediumis circulated, a steam ejector for evacuating said chamber to lower thetemperature of the refrigerating medium as it passes therethrough, meansfor condensing the steam discharged from said ejector and means,operative upon a reduction in the capacity of said means last named tosuch a degree that it fails to condense saidsteamQfor stopping thecirculation of the refrigerating medium through said apparatus. 1

3. The combination with refrigerating apparatus, of equipment forcooling the refrigerating medium which is circulated through saidapparatus including a chamber through which said refrigerating medium iscirculated, a steam ejector for evacuating said chamber to lower thetemperature of the refrigerating medium as it passes therethrough, acondenser into which the steam from said ejector is d'scharged and inwhich said steam is condensed, means for maintaining a vacuum in saidcondenser and means, operative upon a reduction in the capacity of saidcondenser to such a degree that it fails to condense said steam, forstopping the c'rculation of the refrigerating medium through saidapparatus;

4.-'I'he combination with refrigerating apparatus, of equipment forcooling the refrigerating medium which is circulated through sa'dappasteam in said chamber for stopping the circulation of saidrefrigerating medium through said apparatus.

5. The combination with. refrigerating apparatus, of equipment forcooling the refrigerating medium which is circulated through saidapparatus including a chamber through which said refrigerating medium iscirculated, a steam ejector for evacuating said chamber to lower thetemperature of the refrigerating medium as it is circulatedtherethrough, a steam supply line for said ejector, means forautomatically medium which is determined value, a condenser into whichthe steam from said ejector is discharged and means operative upon thebacking up of steam in said chamber for stopping the circulation of saidrefrigerating medium through said apparatus.

6. The combination with refrigerat ng apparatus, of equipment forcooling the refrigerating medium which is circulated through saidapparatus including a chamber through which said refrigerating medium iscirculated, a steam ejector for evacuating said chamber to lower thetemperatureof the refrigerating medium as it passes therethrough, acondenser into which the steam from said ejector is discharged, meansfor maintaining a vacuum in said condenser, means for circulatng acooling medium through said condenser and'means operative upon thebacking up of steam in said chamber for stopping the circulating of saidrefrigerating medium through said apparat 7. Thecombination withrefrigeratng apparatus, of equipment for cooling the refrigeratingmediumwhich is circulated through said apparatusincluding a chamberthrough which said refrigerat'ng medium is circulated, a steam ejectorfor evacuating said chamber to lower the temperature of therefrigerating medium as it is circulated therethrough', a steam supplyline for said ejector, means for automatically controlling the supply ofsteam from said line to said ejector so as to maintain the temperatureof the refigerating medium at a predetermined value, a condenser intowhich the steam from said ejector discharges, means for maintaining avacuum in said condenser, means for circulating a cooling medium throughsaid condenser and means operative upon the backing up of steam in saidchamber for stoppng the circulation of said refrigerating medium throughsaid apparatus.

8. The combination with refrigerating apparatus, of equipment forcooling the refrigerating circulated through said apparatus including achamber through which said refrigerating medium is circulated, a steamejector for evacuating said chamber to lower the temperature of therefrigerating medium as it passes therethrough, a condenser into whichthe steam from said ejector is discharged, a valve for controlling thecirculation of the refrigerating medium through said apparatus and atemperature responsive element for closing said valve when steam fromsaid ejector backs up in said chamber, said element being located insaid chamber above the level of the refrigerating medium.

9. The combination with' refrigerating apparatus, of equipment forcooling the refrigerating medium which is circulated through saidapparatus including a chamber through which said refrigerating medium iscirculated, a steam ejector for evacuating said chamber to lower thetempcrature of the refrigerating medium as it passes therethrough, asteam supply line for said ejector,

a valve in said line, a temperature responsive element for controllingsaid valve, said element being immersed in the refrigerating medium insaid chamber and being adapted to open said valve when the temperatureof said medium raises to a predetermined value,'a condenser into whichsaid ejector discharges, means for maintaining a vacuum in saidcondenser, a second. valve for controlling the circulation of therefrigerating medium through said apparatus and a temperature responsiveelement for closing said valve to stop the circulation of therefrigerating medium through said apparatus when steam from said ejectorbacks up in said chamber, said element being located in said chamberabove the level of said refrigerating medium 10. The combination withrefrigerating apparatus, of equipment for cooling the refrigeratingmedium which is circulated throughsaid appara-' tus including a chamberthrough which said refrigerating medium is circulated, a steamxejector,

for evacuating said chamber to lower thjtemperature of the refrigeratingmedium as it passes therethrough, a condenser into which the steam, fromsaid ejector discharges, means for maintain ing a vacuum in saidcondenser and means, operative upon the absolute pressure in saidcondenser increasing to such a value that a back flow of steam into saidchamber is likely, for stopping the circulation of said refrigeratingmedium through said apparatus.

11. The combination with refrigerating apparatus, of equipment forcooling the refrigerating medium which is circulated through saidapparatus including a chamber through'which said refrigerating medium iscirculated, a steam ejector for evacuating said chamber to lower thetemperature of the refrigerating medium as it passes therethrough, acondenser into which the steam from said ejector is discharged and inwhich said steam is condensed, means for maintaining a vacuum in saidcondenser, means for circulating cooling water through said condenser,said means including a pump, a cooling tower and means connecting thecondenser, pump and cooling tower in a circuit, whereby cooling waterfrom said tower is circulated continuously through the condenser andmeans, operative when the temperature of the cooling water which-isintroduced into the condenser increases to a value at which thecorresponding absolute pressure in the condenser is such that a backflow of the steam is created, for stopping circulation of therefrigerating medium through said apparatus.

HAROLD M. GRAHAM.

